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example picture

I'd assume insufficient z offset but some areas of the first layer look fine. I've been struggling with this problem despite lots of attempts including z offset, infill overlap, belt retensioning, etc.

Anyone else experienced this type of issue and have suggestions to fix it properly?

I'm using polylite PLA and a E3D steel nozzle. 60 °C bed temp, 230 °C first layer.

Edit: Print speed is 30 mm/s first layer, 60 mm/s normal. This issue occurs on the first few layers then the rest get increasingly better, with the final layer being excellent.

Edit2: Despite lowering the temp to 205--210 and increasing the z offset downwards, the problem persists, though to a lesser degree. Just gaps at ends of infill lines and between straight and circular walls. But seems it only occurs on the lower left and upper right (birds eye view) of the print.

enter image description here

Edit3: The lower left and upper right being further from the nozzle coincides with my removal process using the knife on the lower left and upper right.. Maybe this part of the problem I'll have to bend back in place?

Nozzle bed measurements below:

enter image description here

Edit4: Optimizing the Z offset according to the first layer thickness remained only a partial solution especially as my bed unevenness (1mm+) was past the auto-leveling limitations (<0.5mm), but I found a great thread (link below) with a "correct" solution that worked for a lot of people! After I try this I will come back and write about my experience with the solution.

https://forum.lulzbot.com/viewtopic.php?f=36&t=7904&hilit=bed+leveling+SOLVED

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  • $\begingroup$ Welcome to 3dPrinting.SE! Wow, 230 °C seems a LOT hot for printing PLA filament. You might want to try it in the 190-200 °C area. I don't know if this will fix your overall issue, but it's a good place to start. Also, you don't mention your print speeds. Would be helpful to know. $\endgroup$ – Pᴀᴜʟsᴛᴇʀ2 Jul 24 '19 at 16:54
  • $\begingroup$ Is the problem ONLY on the first layer, or do you have the same problem on SOME layers, or on ALL layers? $\endgroup$ – Davo Jul 24 '19 at 17:34
  • $\begingroup$ try to print at 195°C and speed of 60mm/s. the Z layer height should be 80% of your nozzle size as maximum, if lower is better. $\endgroup$ – Fernando Baltazar Jul 24 '19 at 17:54
  • $\begingroup$ Thanks for warm welcome paulster. I've added print speed info and I'll try lowering the print temp as you and fernando suggested and get back with the results. $\endgroup$ – openyk Jul 24 '19 at 18:17
  • $\begingroup$ Davo I think the problem only occurs severely on the first few layers but what makes it weird is, say on the 5th layer there's only gaps in some areas and other areas are fine. It gets increasingly better until the final several layers which are actually great. $\endgroup$ – openyk Jul 24 '19 at 18:22
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From the picture it is clearly seen that the filament is not flattened properly. This implies that your nozzle bed distance is too large. Try decreasing the gap by leveling the bed at temperature and have a piece of "A4" or "Letter" print paper between the nozzle and bed have a little friction when pulled.

Also reduce the temperature, 230 °C is too hot for PLA (unless your printer temperature is way off, but that is not very likely), try 200 °C.

Another thing that you could check is if the extruded length is exactly what is instructed to be extruded; i.e. calibrate the extruder.

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White PLA is some of the nastiest stuff to print with, it's very impure. Could you try to make the same print, but with another filament?

230 degrees might be a bit too high of a temperature, normally PLA is printed between 215-225. Try to decrease and increase the temperature with 5 degrees to see if there is any differences as well.

Also, could you show us a completely flat, 1 layer print? Basically just a rectangle. Basically I want to see your first layer height.

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